串列多圆柱气动力干扰效应的试验研究

Tests for aerodynamic force interference effect of tandem cylinders

通过刚性模型测压风洞试验,在均匀流场中对比研究了不同数量和不同间距串列多圆柱气动力的干扰效应。串列多圆柱两相邻圆柱的中心距L与圆柱的直径D之比L/D的变化范围为1.2~12.0。圆柱数量的变化范围为1~4。试验的雷诺数为3.4×10^(4)。试验结果发现:串列多圆柱发生流态切换的临界间距比(L/D)cr为3.5~4.0,在临界间距附近,前两个圆柱的时均阻力系数和脉动升力系数突升,其余圆柱则突降,所有圆柱的斯托罗哈数均突升;气动干扰对串列多圆柱时均阻力系数和斯托罗哈数的影响主要表现为减小效应;后方干扰圆柱数量的增加对上游第一个圆柱气动力的影响基本可以忽略;前方干扰圆柱数量的增加对下游最后一个圆柱的气动力影响显著。

Through wind tunnel tests of rigid model pressure measurement,aerodynamic force interference effects of tandem cylinders with different numbers and spacings in uniform flow field were studied.It was shown that the ratio L/D of the center distance between adjacent cylinders L to cylinder diameter D changes from 1.2-12.0;the number of cylinders varies from 1-4;Reynolds number is 3.4×10^(4).Test results showed that the critical spacing ratio(L/D)cr for flow state switching of tandem cylinders is 3.5-4;near the critical spacing,time average drag coefficient and fluctuating lift coefficient of the first two cylinders increase sharply,while the others drop sharply,and Strouhal number of each cylinder rises abruptly;the effect of aerodynamic force interference on time average drag coefficient and Strouhal number of tandem cylinders mainly reveals a reduction effect;effects of increase in the number of rear interference cylinders on the aerodynamic force of the first upstream cylinder can be ignored,while increase in the number of front interference cylinders has a significant impact on aerodynamic force of the last downstream cylinder.